Results in Materials最新文献_第4页

Upcycling of electro discharge machining sludge for metal powder manufacturing–Filtration, washing and separation 金属粉末制造用电火花加工污泥的升级利用——过滤、洗涤、分离

Results in Materials

Pub Date : 2025-12-20 DOI: 10.1016/j.rinma.2025.100877

Oliver Voigt, Thomas Buchwald, Malena Staudacher, Urs Alexander Peuker

Sludges from electro discharge machining were processed to reuse metallic particles. The sludge was characterized before dissolving the dielectric with acetone or isopropanol. Pressure filtration experiments were carried out and filter cake resistances computed. To improve material quality, filter cakes were submitted to displacement washing and dilution washing. All filtrates were collected and investigated. Processed particles were visually investigated by scanning electron microscopy and chemically regarding their carbon and oxygen content. Afterward, dry particles were separated by sieving and sifting, fractions analyzed and the separation characterized. Specific filtration resistances show values of 10¹⁴m⁻². Isopropanol significantly increased processing times compared to acetone. Filter cake washing led to slight improvements of surface quality of particles. For displacement washing, better results were achieved for acetone with approx. 99.5 % removed impurities. Carbon and oxygen contents were in a good range using acetone. Using isopropanol led to detrimentally increased oxygen contents. Particles were separated into fractions for further applications in additive manufacturing. The sifting device applied exhibits a high separation efficiency, with a high sharpness parameter. Several parameter sets were developed for separating particle sizes and powder mixtures. Thermal treatment removed carbon contaminations and oxygen layers on particle surfaces. This work provides a flow scheme for processing oily metallic sludges to obtain a secondary raw material powder.

对电火花加工产生的污泥进行处理，回收金属颗粒。在用丙酮或异丙醇溶解电介质之前，对污泥进行了表征。进行了压滤实验，计算了滤饼阻力。为提高滤饼的质量，对滤饼进行置换洗涤和稀释洗涤。收集所有滤液并进行调查。通过扫描电子显微镜和化学方法对加工后的颗粒进行了碳和氧含量的视觉研究。然后，通过筛分和筛分分离干燥颗粒，分析馏分并对分离进行表征。比过滤电阻值为1014m−2。与丙酮相比，异丙醇显著增加了加工时间。滤饼洗涤后颗粒表面质量略有改善。对于置换洗涤，对丙酮的洗涤效果较好。杂质去除率99.5%。使用丙酮时，碳和氧含量在一个很好的范围内。使用异丙醇会有害地增加氧含量。颗粒被分离成分数，以进一步应用于增材制造。所采用的筛分装置具有较高的分离效率和较高的锐度参数。开发了用于分离粒度和粉末混合物的几个参数集。热处理去除颗粒表面的碳污染和氧层。本工作提供了一种处理含油金属污泥以获得二次原料粉末的流程方案。

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引用次数: 0

Study of UV-induced surface modification of polyethylene and polytetrafluoroethylene 紫外光诱导聚乙烯和聚四氟乙烯表面改性的研究

Results in Materials

Pub Date : 2025-12-19 DOI: 10.1016/j.rinma.2025.100876

S. Jamali , S.S. Ghaffari-Oskooei , S. Allahyari

Surface modification of polymers is essential for improving their interfacial properties without compromising bulk performance. This study investigates the effects of ultraviolet UV irradiation on the surface characteristics of polyethylene PE and polytetrafluoroethylene PTFE with the objective of understanding the relationship between UV-induced surface modifications and changes in wettability, chemical composition, and morphology. PE and PTFE samples were exposed to controlled UV treatment, and their surface properties were analyzed using water contact angle WCA measurements, Fourier-transform infrared spectroscopy FTIR, and atomic force microscopy AFM. Results showed that UV treatment led to a significant decrease in the water contact angle of PE, with a 106 % reduction, reflecting an increase in hydrophilicity. In contrast, PTFE exhibited a more moderate 60 % decrease in WCA, indicating limited enhancement in wettability. FTIR analysis revealed the formation of oxygen-containing functional groups in both polymers, with PE showing a more pronounced incorporation of these groups. The surface roughness of PE increased by 180 %, from 42 nm to 118 nm, whereas PTFE showed a more modest increase of 89 %. The AFM analysis confirmed a significant increase in nanoscale roughness for PE, while PTFE exhibited minimal morphological changes.

This comparative analysis highlights the strong influence of polymer chemistry on UV-induced surface modification mechanisms. These findings demonstrate that PE is more responsive to UV irradiation, with significant alterations that lead to enhanced surface energy and wettability. In contrast, PTFE, due to its stable C-F bonds, undergoes slower and more limited modifications, primarily in the chemical domain. The study underscores the importance of material selection for applications in UV-rich environments, with PE being more suitable for applications requiring enhanced hydrophilicity, while PTFE is better suited for environments requiring UV durability. The insights gained from this work can be directly applied to the development of advanced coatings, adhesion technologies, and biomedical interfaces.

聚合物的表面改性对于改善其界面性能而不影响整体性能至关重要。本研究研究了紫外线照射对聚乙烯PE和聚四氟乙烯PTFE表面特性的影响，目的是了解紫外线诱导的表面修饰与润湿性、化学成分和形态变化之间的关系。将PE和PTFE样品置于可控紫外处理下，利用水接触角WCA测量、傅里叶变换红外光谱FTIR和原子力显微镜AFM分析其表面性能。结果表明，UV处理导致PE的水接触角显著降低，降低了106%，反映了亲水性的增加。相比之下，PTFE的WCA下降了60%，表明润湿性的增强有限。FTIR分析显示，两种聚合物中都形成了含氧官能团，PE显示这些官能团的结合更为明显。PE的表面粗糙度增加了180%，从42 nm增加到118 nm，而PTFE的表面粗糙度增加了89%。AFM分析证实PE的纳米级粗糙度显着增加，而PTFE表现出最小的形态变化。这一对比分析突出了聚合物化学对紫外线诱导的表面改性机制的强烈影响。这些发现表明，PE对紫外线照射更敏感，其表面能和润湿性显著增强。相比之下，聚四氟乙烯，由于其稳定的C-F键，经历更缓慢和更有限的修饰，主要是在化学领域。该研究强调了在富紫外线环境中应用材料选择的重要性，PE更适合需要增强亲水性的应用，而PTFE更适合需要紫外线耐久性的环境。从这项工作中获得的见解可以直接应用于先进涂层、粘附技术和生物医学界面的开发。

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引用次数: 0

Developing a novel hybrid ensemble machine learning model for predicting reduced elongation of low-carbon steel in hydrogen environments 开发一种新的混合集成机器学习模型，用于预测低碳钢在氢环境中的延伸率降低

Results in Materials

Pub Date : 2025-12-19 DOI: 10.1016/j.rinma.2025.100871

Zainab Iyiola, Ramadan Ahmed, Catalin Teodoriu, Nayem Ahmed

Hydrogen embrittlement (HE) poses a substantial challenge to the structural integrity and ductility of low-carbon steel, particularly in the context of hydrogen transport infrastructure. This study introduces a pioneering hybrid ensemble machine learning (ML) model specifically developed to predict the reduced elongation of low-carbon steel in a hydrogen environment with enhanced accuracy and robustness. Seven individual ML models were developed, including Random Forest, Decision Tree, K-Nearest Neighbors (KNN), Gradient Boosting, CatBoost, XGBoost, and Support Vector Regression (SVR). A novel model selection framework that holistically integrates feature importance, R², RMSE, and MAE metrics was used to identify Gradient Boosting and KNN as the top-performing models. These were subsequently combined using a weighted soft voting approach to develop a new hybrid ensemble model. The resulting hybrid model achieved a training R² of 0.89 and a test R² of 0.87, with RMSE and MAE values of 4.45 and 3.16, respectively. This research represents the first comprehensive integration of hybrid ensemble learning for predicting hydrogen-induced ductility loss in steels, providing a powerful data-driven solution to enhance the reliability of hydrogen transport infrastructure.

氢脆（HE）对低碳钢的结构完整性和延展性提出了重大挑战，特别是在氢运输基础设施的背景下。本研究介绍了一种开创性的混合集成机器学习（ML）模型，专门用于预测低碳钢在氢环境中的延伸率降低，具有更高的准确性和鲁棒性。开发了7个独立的ML模型，包括随机森林、决策树、k近邻（KNN）、梯度增强、CatBoost、XGBoost和支持向量回归（SVR）。一个全新的模型选择框架，整体集成了特征重要性、R2、RMSE和MAE指标，用于识别梯度增强和KNN作为表现最好的模型。随后使用加权软投票方法将这些组合起来，以开发新的混合集成模型。混合模型的训练R2为0.89，检验R2为0.87，RMSE为4.45，MAE为3.16。该研究首次全面集成了混合集成学习，用于预测钢中氢引起的延性损失，为提高氢运输基础设施的可靠性提供了强大的数据驱动解决方案。

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引用次数: 0

Spark plasma sintering of ZnO varistors: Parameter optimization via Taguchi method and correlation with microstructure and electrical characteristics 火花等离子烧结ZnO压敏电阻器：基于田口法的参数优化及其与微结构和电学特性的关系

Results in Materials

Pub Date : 2025-12-19 DOI: 10.1016/j.rinma.2025.100855

Arash Vaghef-Koodehi

Spark plasma sintering (SPS) was employed to fabricate ten-component ZnO-based varistors with enhanced microstructural uniformity and electrical functionality. The rapid densification achieved under optimized SPS conditions (850 °C/10 min/50 MPa), followed by annealing at 650 °C for 1 h in air, ensured complete re-oxidation of boundary-forming phases and eliminated carbon-related artifacts. This processing route produced highly homogeneous grain-boundary networks enriched with Bi, Sb, Ni, and Co, leading to stable double-Schottky barriers across the microstructure. The resulting ceramics exhibited a marked improvement in nonlinear response. The SPS-850 °C specimen delivered the highest nonlinearity coefficient (α ≈ 43), elevated breakdown field strength, and a significantly reduced leakage current (9.2 μA cm⁻²), outperforming counterparts processed through conventional sintering regimes. The superior electrical behavior is attributed to the combined effects of rapid, controlled densification and a carefully balanced multi-oxide additive system that governs grain-boundary chemistry and suppresses barrier inhomogeneity. Overall, the study demonstrates that SPS, when synergistically integrated with engineered additive chemistry and a post-sintering annealing step, provides a robust pathway for producing next-generation ZnO varistors with high reliability and advanced surge-protection capability.

采用火花等离子烧结（SPS）法制备了十组分zno基压敏电阻器，提高了微结构均匀性和电学功能。在优化的SPS条件（850°C/10 min/50 MPa）下实现快速致密化，然后在650°C空气中退火1小时，确保了边界形成相的完全再氧化，并消除了碳相关的伪影。这种加工路线产生了富含Bi、Sb、Ni和Co的高度均匀的晶界网络，从而在微观结构中形成稳定的双肖特基势垒。所得陶瓷在非线性响应方面表现出明显的改善。SPS-850°C样品具有最高的非线性系数（α≈43），击穿场强提高，泄漏电流显著降低（9.2 μA cm−2），优于通过常规烧结工艺处理的样品。优异的电学性能归功于快速、可控的致密化和精心平衡的多氧化物添加剂系统的综合作用，该系统控制晶界化学并抑制势垒不均匀性。总的来说，该研究表明，当SPS与工程添加剂化学和烧结后退火步骤协同集成时，为生产具有高可靠性和先进浪涌保护能力的下一代ZnO压敏电阻提供了一个强大的途径。

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引用次数: 0

Effect of the chemical composition of multilayer Ni/Al foil on its deformation behaviour during heating under load 多层Ni/Al箔的化学成分对其加载加热变形行为的影响

Results in Materials

Pub Date : 2025-12-17 DOI: 10.1016/j.rinma.2025.100875

Tetiana Melnychenko, Anatolii Ustinov

Multilayer foils (MFs) derived from reaction systems such as Ni/Al are promising interlayers for forming permanent joints by soldering or diffusion bonding. To obtain soldered joints in the MF, a self-propagating high-temperature synthesis (SHS) reaction is initiated. During diffusion bonding, the reaction-diffusion in the MF is controlled by external heating of the joint zone, thereby reducing heat generation there. The authors of many works showed that, in addition to the MF effect on diffusion processes in the welded zone, there is a correlation between the deformation behaviour of MFs and joint-process parameters. In this work, the impact of the chemical composition of the MF on its deformation behaviour during heating under constant load conditions was investigated using the Ni/Al MF with component ratios of 1:3, 1:1, and 3:1, corresponding to the intermetallics Al₃Ni, AlNi, and AlNi₃, respectively. It was shown that the deformation behaviour of MFs changes drastically with an increase in the nickel content from 1:3 to 3:1, due to the activation of various plastic deformation mechanisms. It turns out that the monotonic increase in the rate of plastic deformation upon heating of MF with a ratio of 1:3 is due to its superplastic flow by the mechanism of intergranular slip. The non-monotonic temperature dependence of the rate of deformation of MF with a ratio of 1:1 or 3:1 is realised by both the mechanism of intergranular slip and superplastic flow due to phase transformations that occur only within certain temperature intervals.

从Ni/Al等反应体系中衍生出的多层箔（MFs）是通过焊接或扩散键合形成永久接头的有前途的中间层。为了在MF中获得焊接接头，引发了自传播高温合成反应（SHS）。扩散键合过程中，MF内的反应扩散由接合区外部加热控制，从而减少了接合区产生的热量。许多研究表明，除了MF对焊接区扩散过程的影响外，MF的变形行为与焊接过程参数之间存在相关性。在这项工作中，研究了恒载条件下加热时MF的化学成分对其变形行为的影响，采用成分比分别为1:3,1:1和3:1的Ni/Al MF，分别对应于金属间化合物Al3Ni， AlNi和AlNi3。结果表明，随着镍含量从1:3增加到3:1，由于多种塑性变形机制的激活，MFs的变形行为发生了急剧变化。结果表明：加热后塑性变形速率以1:3的比例单调增加是由于其以粒间滑移机制进行的超塑性流动。变形速率的非单调温度依赖性为1:1或3:1，是通过晶间滑移和超塑性流动机制实现的，这是由于相变仅在一定温度区间内发生。

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引用次数: 0

Prediction of compressive strength of alternative concretes of calcium sulfoaluminate cements cured under different conditions 不同养护条件下硫铝酸钙水泥替代混凝土抗压强度预测

Results in Materials

Pub Date : 2025-12-17 DOI: 10.1016/j.rinma.2025.100858

Ricardo X. Magallanes-Rivera , Marisol Gallardo-Heredia , Ulises Avila-López , Yadira G. Maldonado , Oziel Gómez

In this work a statistical model was determined to predict the compressive strength of calcium sulfoaluminate concretes cured under different solutions: distilled water, tap water, 0.5 N HCl, and 0.5 N H₂SO₄. The different storage solutions and time were the independent variables in the study involving mechanical aspects and durability approaches. The concretes were prepared under ACI and ASTM standards, water/binder ratios of 0.5, 0.7 and 0.9 were used, and fine/coarse aggregate proportions of 0.9–1.3 were used. Compressive strength tests were performed after 1, 7, 14, 28, and 90 days of curing. The analysis was developed using the multiple linear regression statistical method. The multivariate power function model was expressed as a function of time for the different experimental conditions used in the manufacture of the mixtures such as the sand/gravel and the water/cement ratios. The equations express outcomes for the estimation of compressive strength that fits correctly with the experimental results. The results indicate that the models mostly explain the variability of the strength in the mixtures in the ranges of 89–99 %, except for curing in H₂SO₄ where it only adjusts to 33 %, evidencing the deterioration suffered by the specimens under this attack.

本文建立了一个统计模型来预测硫铝酸钙混凝土在不同溶液（蒸馏水、自来水、0.5 N HCl和0.5 N H2SO4）下的抗压强度。不同的储存方案和时间是研究中涉及机械方面和耐久性方法的独立变量。混凝土按ACI和ASTM标准配制，水胶比分别为0.5、0.7和0.9，细粗骨料比为0.9 ~ 1.3。分别在养护1、7、14、28和90天后进行抗压强度试验。采用多元线性回归统计方法进行分析。多元幂函数模型表示为制造混合物时使用的不同实验条件（如砂/砾石和水/水泥比）的时间函数。该方程所表达的抗压强度估算结果与试验结果吻合较好。结果表明，除了在H2SO4中养护时强度仅调整到33%外，这些模型大部分解释了混合物强度在89 - 99%范围内的变化，证明了试样在这种攻击下遭受的劣化。

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引用次数: 0

Effects of temperature and NaBH4 concentration on synthesis of Cu2O nanoparticles by polyol method 温度和NaBH4浓度对多元醇法制备纳米Cu2O的影响

Results in Materials

Pub Date : 2025-12-17 DOI: 10.1016/j.rinma.2025.100861

A.S.M.J. Islam , M.A. Islam , A.S.M.S. Rahman , M.A. Gafur

Cuprous oxide nanoparticles have been prepared through polyol synthesis process using CuSO₄·5H₂O as precursor, ethylene glycol as solvent, polyvinylpyrrolidone as surfactant and NaBH₄ as reducing agent at temperature range of 66 to 135°. Initially, the formation of Cu₂O has been ascertained when the colour of the solution changes from blue to green, orange, and red. The synthesized Cu₂O nanoparticles are characterized for various properties where average crystallite sizes are from 14 nm to 33 nm and lattice constant is 0.43 nm. At reaction temperature of 85 °C and above, all samples have formed nanoparticles and well matched with the existing XRD data. The crystallite size of Cu₂O nanoparticles decreases simultaneously with the increase of solution temperature and concentration of reducing agent. The band gap energies of Cu₂O at 85 °C range from 1.75 to 2.67 eV having the highest absorbance of 3.65 au. Elementary analysis shows the percentage and ratio of Cu and O are consistent to form Cu₂O nanoparticles, variances are due to presence of other nanoparticles. Results indicate that the reaction temperature of 85 °C is most suitable to synthesize Cu₂O nanoparticles utilizing polyol synthesis method.

以CuSO4·5H2O为前驱体，乙二醇为溶剂，聚乙烯吡咯烷酮为表面活性剂，NaBH4为还原剂，在66 ~ 135℃的温度范围内，采用多元醇合成工艺制备了氧化亚铜纳米颗粒。最初，当溶液的颜色从蓝色变为绿色、橙色和红色时，确定了Cu2O的形成。合成的Cu2O纳米颗粒具有不同的性能，平均晶粒尺寸在14 ~ 33 nm之间，晶格常数为0.43 nm。在85℃及以上的反应温度下，所有样品均形成纳米颗粒，与现有XRD数据匹配良好。随着溶液温度和还原剂浓度的升高，纳米Cu2O晶粒尺寸减小。Cu2O在85℃时的带隙能范围为1.75 ~ 2.67 eV，吸光度最高为3.65 au。元素分析表明，Cu和O的百分比和比例形成Cu2O纳米粒子是一致的，差异是由于其他纳米粒子的存在。结果表明，用多元醇法合成纳米Cu2O最适宜的反应温度为85℃。

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引用次数: 0

Phase transfer study on the effects of metal ions on storage hardening of natural rubber 金属离子对天然橡胶贮存硬化影响的相转移研究

Results in Materials

Pub Date : 2025-12-16 DOI: 10.1016/j.rinma.2025.100872

Bualoy Chanpaka , Krisda Suchiva , Supa Wirasate

The storage hardening of natural rubber (NR) has long been investigated; however, its mechanism remains unclear. Most work has focused on proteins and phospholipids, whereas the role of metal ions is poorly understood. This study, therefore, examined the metal-ion effect under real storage conditions. Phase transfer (PT) experiments were used to evaluate their influence. PTNR samples showed that about 2.6 % of Mg²⁺, 63.2 % of Ca²⁺, and 31.1 % of Fe²⁺ were transferred to the organic phase with NR. Except for Fe²⁺, the metal ions added were hardly transferred. PT samples contained 0.02–0.05 % nitrogen, indicating that bonded proteins moved with NR, whereas free ones remained in the aqueous phase. The storage modulus (G′) measurements showed pronounced storage hardening in WNR, with G′ increasing by 25–40 kPa over 2 months. In contrast, PTNR and metal-PTNR exhibited only minimal changes (±10 kPa), indicating stable viscoelastic behavior. The gel content of PT samples (1.5–1.9 %) was lower than that of WNR (6.0–6.2 %), and showed no significant change during storage. These findings showed that the residual bonded proteins and metal ions (Mg²⁺, Ca²⁺, and Fe²⁺) did not contribute significantly to the storage hardening, suggesting that the phenomenon originated from interactions involving other non-rubber constituents rather than intrinsic polyisoprene properties.

天然橡胶（NR）的贮存硬化研究由来已久；然而，其机制尚不清楚。大多数研究都集中在蛋白质和磷脂上，而金属离子的作用却知之甚少。因此，本研究在实际储存条件下检验了金属离子效应。采用相转移（PT）实验对其影响进行了评价。PTNR样品表明，约有2.6%的Mg2+、63.2%的Ca2+和31.1%的Fe2+与NR一起转移到有机相，除Fe2+外，添加的金属离子几乎没有转移。PT样品含氮量为0.02 - 0.05%，表明结合蛋白随NR移动，而游离蛋白则留在水相中。存储模量（G′）测量结果显示，WNR中的存储硬化明显，G′在2个月内增加了25-40 kPa。相比之下，PTNR和金属-PTNR仅表现出最小的变化（±10 kPa），表明稳定的粘弹性行为。PT样品的凝胶含量（1.5 ~ 1.9%）低于WNR样品（6.0 ~ 6.2%），且在贮藏过程中无显著变化。这些发现表明，剩余的结合蛋白和金属离子（Mg2+， Ca2+和Fe2+）对储存硬化没有显著的贡献，这表明这种现象源于其他非橡胶成分的相互作用，而不是固有的聚异戊二烯性质。

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引用次数: 0

Wear evaluation and mechanical properties of Al/B2O3+TiO2 hybrid surface composite fabricated via solid-state friction stir processing 固态搅拌摩擦法制备Al/B2O3+TiO2杂化表面复合材料的磨损性能及力学性能

Results in Materials

Pub Date : 2025-12-16 DOI: 10.1016/j.rinma.2025.100874

Siamak Pedrammehr , Moosa Sajed , Ahad Zare Jond , Sajjad Pakzad

Aluminum alloys are widely used in industry due to their favorable strength-to-weight ratio, but their relatively weak surface properties, particularly poor wear resistance, limit broader applications. Conventional fusion-based reinforcement methods often introduce microstructural defects and reduce mechanical performance. This study aimed to enhance the surface properties of 1050 aluminum alloy by fabricating mono and hybrid surface composites using solid-state friction stir processing (FSP) with titanium dioxide (TiO₂) and boron trioxide (B₂O₃) nanopowders. Reinforcement ratios and the number of FSP passes were systematically varied, and the resulting composites were characterized through tensile testing, Vickers microhardness measurements, wear testing, and metallographic analysis. The results showed that three-pass FSP significantly increased tensile strength, hardness, and wear resistance compared to single-pass processing. Hybrid composites consistently outperformed mono composites, with the TB33 configuration (75 % TiO₂–25 % B₂O₃, three passes) achieving the highest tensile strength (112 MPa), hardness (49.26 HV), and balanced ductility (16 %), while TB23 (50 %–50 %) exhibited superior wear resistance and B3 (100 % B₂O₃) provided the greatest elongation (33 %). These findings demonstrate that the optimal reinforcement composition is application-dependent, and that hybrid reinforcement combined with multi-pass FSP offers a viable pathway to tailor mechanical and tribological properties of aluminum alloys for diverse engineering uses.

铝合金由于其良好的强度重量比在工业上得到了广泛的应用，但其相对较弱的表面性能，特别是耐磨性差，限制了其更广泛的应用。传统的基于熔合的加固方法往往会引入微结构缺陷，降低力学性能。本研究以二氧化钛（TiO2）和三氧化二硼（B2O3）纳米粉体为原料，采用固体搅拌摩擦处理（FSP）制备单组分和杂化表面复合材料，以提高1050铝合金的表面性能。系统地改变增强率和FSP次数，并通过拉伸测试、维氏显微硬度测量、磨损测试和金相分析来表征所得到的复合材料。结果表明，与单道次加工相比，三道次FSP显著提高了拉伸强度、硬度和耐磨性。混合复合材料的性能一直优于单一复合材料，TB33结构（75% tio2 - 25% B2O3，三道次）具有最高的抗拉强度（112 MPa），硬度（49.26 HV）和平衡的延展性（16%），TB23（50% - 50%）具有优异的耐磨性，B3 （100% B2O3）具有最大的伸长率（33%）。这些发现表明，最佳的增强成分取决于应用，混合增强与多道次FSP的结合为定制铝合金的机械和摩擦学性能提供了可行的途径，以适应不同的工程用途。

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引用次数: 0

Phase and microstructure formation in WC-Co cemented carbide tools via cold isostatic pressing 冷等静压WC-Co硬质合金刀具的相与组织形成

Results in Materials

Pub Date : 2025-12-16 DOI: 10.1016/j.rinma.2025.100865

Vitalii Sheremet , Gennadiy Akimov , Ihor Andreiev , Yurii Besarabets , Serhii Studenets , Iryna Trosnikova , Petro Loboda

WC-Co cemented carbides exhibit a combination of high hardness, strength, and fracture toughness due to the synergistic composition effect of the hard tungsten carbide phase and the ductile cobalt binder. The cobalt binder typically contains both hexagonal and cubic polymorphic modifications, whose distinct mechanical and service properties make phase ratio control a key factor in enhancing tool performance. This study explores the use of cold isostatic pressing (CIP) of WC-Co green compacts before sintering as a method to enhance the properties of cemented carbides. A comparative analysis was carried out between cermets compacted via uniaxial pressing (UP) and those subjected to CIP before sintering. The results revealed that CIP significantly refined WC grain size in WC-8Co cermet, reducing it by 57 % from 2.3 μm to 1.0 μm. In both WC-8Co and WC-15Co cemented carbides, which were subjected to CIP, cobalt predominantly existed in the hexagonal polymorphic modification, in contrast to the cubic structure stabilized in alloys compacted solely by UP. Due to the structural changes, the mean transverse rupture strength (TRS) of CIP-ed WC-8Co and WC-15Co increased by 9 % (to 1980 MPa) and 13 % (to 2410 MPa), respectively. Cutting tools and burnishing tools were fabricated from WC-8Co and WC-15Co cemented carbides, respectively. Compared to tools compacted solely by UP, the wear rates of CIP-ed WC-8Co and WC-15Co tools were reduced by 67 % and 44 %, respectively. Overall, these findings demonstrate the effectiveness of CIP as a method for tailoring the microstructure of WC-Co cermets, significantly improving their wear resistance under severe contact loading conditions.

由于硬质碳化钨相和韧性钴结合剂的协同组成作用，WC-Co硬质合金具有较高的硬度、强度和断裂韧性。钴结合剂通常包含六方和立方多晶改性，其独特的机械和使用性能使相比控制成为提高工具性能的关键因素。本研究探讨了在烧结前对WC-Co绿坯进行冷等静压（CIP）来提高硬质合金性能的方法。对烧结前单轴压实与CIP压实的陶瓷进行了对比分析。结果表明，CIP显著细化WC- 8co陶瓷的WC晶粒尺寸，使WC晶粒尺寸从2.3 μm减小到1.0 μm，降幅达57%；在经过CIP压实的WC-8Co和WC-15Co硬质合金中，钴主要以六边形多晶态改性存在，而仅仅经过UP压实的合金则以立方结构稳定存在。由于结构的改变，CIP-ed WC-8Co和WC-15Co的平均横向断裂强度（TRS）分别提高了9%（达到1980 MPa）和13%（达到2410 MPa）。采用WC-8Co和WC-15Co硬质合金分别制备刀具和抛光刀具。与仅使用UP压实的刀具相比，CIP-ed WC-8Co和WC-15Co刀具的磨损率分别降低了67%和44%。总的来说，这些发现证明了CIP作为一种定制WC-Co陶瓷微观结构的方法的有效性，显著提高了其在严重接触载荷条件下的耐磨性。

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引用次数: 0